initFromString should allow comments in config strings

[shortdudey123]

Problem
It appears that the initFromFile for the mapping config file is only read and then passed to initFromString. That method does not appear to have any way to handle comments in the string (or in this specific thought, the mapping file)

Possible Solution
Support golang style (//) comments in the initFromString and ignore them in the case statement in the if statement

[drawks]

Once yaml config files from #66 are merged it seems like the legacy mapper/config format could/should be put out to pasture. yaml allows for comments among many other improvements in how the data is structured.

I've been writing PRs against the branch in #66 for a few days and it is a big improvement.

[drawks]

#98 resolves this issue by dropping support for legacy style mapper configs in favor of the yaml configs from #66 which support comments.

[grobie]

Thanks!